1. Field of the Invention
The present invention is directed to collapsible containers for packaging and dispensing fluids, particularly liquids and flowable powders. In particular, the present invention is directed to seamless thermoplastic containers for packages, such as a “bag-in-box” and beverage carton liners, and recyclable substitutes for beverage pouches and drink boxes.
2. Related Background Art
Collapsible containers are used for storing and dispensing a variety of fluids, particularly liquids and flowable powders. For example, collapsible containers are used as liners for cartons used for storing beverages and other flowable materials. In addition, collapsible containers are used in “bag-in-box” (“BIB”) applications. A BIB is useful in a variety of applications. For example, relatively inexpensive wines are sold in BIBs, as are concentrates for soft drinks for fountain applications and other post-mix drink dispensers. A soft drink is provided by mixing a metered amount of concentrate from a collapsible container with a measured amount of water. As is well known in the art, the water is often carbonated.
Two particular problems exist with prior art collapsible containers. First, prior art collapsible containers are typically formed from a plurality of thermoplastic sheets that are sealed together, such as by heat sealing or with an adhesive. For example, U.S. Pat. No. 5,749,493 to Boone et al. and U.S. Pat. Nos. 5,941,421, and 6,102,252 to Overman et al. (“the Boone and Overman patents”) disclose a collapsible container made from a pair of flexible sheets that are sealed together. Fluids may be introduced into and removed from the collapsible container through an annular spout disposed through one of the flexible sheets. The spout is attached to the flexible sheet and sealed using an annular flange. This results in seams, where the sheets are joined and around the spout, that are prone to leakage.
In addition, prior art collapsible containers, such as those used with soft drink fountain equipment, can form pockets when they collapse, such that the container cannot drain completely. This often results in waste, increasing the ultimate cost of the product to the consumer. Various methods of decreasing the amount of waste have been proposed. However, they all increase the complexity and cost of the collapsible container. For example, the Boone and Overman patents, discussed above, disclose a collapsible container comprising at least one elongated liquid channel that provides a path for liquid to flow from any part of the container to the container spout. The liquid channels are either one or more ribs or protrusions molded into the inner surface of a panel within the container or a web strip, having at least one pair of ribs, and disposed between the two flexible sheets that make up the opposite sides of the container. Similarly, U.S. Pat. Nos. 5,647,511, 5,915,596, and 6,045,006 to Bond, Credle, Jr., and Frazier et al., respectively, disclose collapsible container type packages having a dip strip to direct liquid in the container to the spout.
U.S. Pat. Nos. 4,696,840 and 5,049,349 to McCullough et al. disclose a bag-in-box composite container in which the inner bag of the container is blow-molded from a thermoplastic preform within the outer box, such that the outer box acts as a blow mold. There is no suggestion that the preform is stretch-blow molded to form the bag; i.e., there is no suggestion that the preform is stretched longitudinally with a stretching rod, as well as expanded by the pressure of a gas. In the disclosed method for forming the bag, an outer carton having an aperture in its top end panel is erected and placed within a restraint, such as a metal band cage or a blow mold. The body portion of the preform is heated and softened, and introduced into the erected carton through the aperture in the end panel. The top portion of the preform remains outside the box. The hot body portion of the preform is then expanded with a fluid, such as a pressurized gas or the fluid contents of the final BIB, into a thin-walled bag within the box.
There is also no teaching or suggestion in either of the McCullough patents that the walls of the disclosed bags are sufficiently thin to allow the bag to collapse as its contents are removed through the spout. Moreover, one of ordinary skill in the art would expect that, upon contact of the hot, expanded preform with the interior surface of the box, the preform and the box surface would be likely to adhere, preventing collapse of the bag when emptied. Rather than teaching that the bag is collapsible, the McCullough patents teach that, where the bag can move within the box, an adhesive can be applied to the inner surface of the box or to the outer surface of the preform prior to blow molding the preform within the box to prevent movement of the bag relative to the box. This would prevent the bag from collapsing in the box as the bag is emptied.
However, collapsible bags are highly desirable for BIBs, as such bags provide a smooth flow of fluid contents from the BIB as the bag collapses. This eliminates the need for air to enter the bag through the spout, as is required in non-collapsible bags, interfering with the flow of the contents from the bag. Therefore, a smooth flow of fluid contents from a BIB having a non-collapsible bag is not possible, as the air that must enter the bag to replace the contents of the bag must bubble through the fluid as it passes through the spout. Where the container is collapsible, no air needs to enter through the spout, as air pressure on the outside of the collapsible container reduces the volume of the container as the contents are removed, maintaining equal pressure within and without the container.
With the exception of the McCullough patents and one embodiment of the Overman patents, each of the disclosed containers requires a separate web or dip strip to channel liquid to the spout of the container, increasing the cost and complexity of the container. In addition, there is no suggestion in any of the patents discussed above of eliminating the seams between opposite sides of the containers and between the spout and the rest of the container to reduce the possibility of leakage. Also, adding a barrier layer, such as an oxygen scavenging layer requires laminating the panels and sealing multiple layers together. Again, this adds to the cost and complexity of the container.
Disposable drink boxes and beverage pouches are also well-known in the art. Typically, a drink box comprises a cardboard box, laminated with plastic, and lined with a metal foil or plastic liner that contains the beverage or drink, typically a non-carbonated juice. The drink within the drink box is typically consumed through a straw. The straw may be inserted into the drink box through a hole in the cardboard box by piercing the liner with an end of the straw. Such a drink box is generally disclosed in U.S. Pat. No. 6,129,265 to Perryman et al. Drink boxes may also comprise a built-in straw, such as that disclosed in U.S. Pat. No. 5,482,202 to Wen.
Similarly, beverage pouches typically comprise laminates of metal foil and plastic, where the edges of the foil and plastic edges are sealed to form the pouch, adding to the cost of the manufacture. As with drink boxes, a small portion of the pouch is configured to allow a straw to pierce the side of the pouch, providing access to the beverage. Such a pouch is disclosed in U.S. Pat. No. 6,116,782 to Arkins et al.
Both drink boxes and beverage pouches are intended to be disposable, and, thus, create a solid waste problem. Unlike bottles for soda and other beverages that are formed from a recyclable plastic, such as PET, laminated drink boxes and beverage pouches are difficult, if not impossible, to recycle, due to the layers of different materials that must be separated. The cost of recycling such containers can be prohibitive.
In addition, once a drink box or beverage pouch is opened, there is typically no way to re-close the container. Therefore, if all of the beverage is not consumed after opening, a potential for spilling exists. As a result, the container is often thrown away while it still contains beverage, increasing the unit cost of the beverage to the consumer, and further complicating recycling.
Therefore, a need exists for a seamless collapsible container that provides for easy and complete evacuation of the contents of BIBs and recyclable substitutes for drink boxes and beverage pouches that can preferably be resealed or closed sufficiently to be leakproof. The present invention provides such containers and methods for making such containers.